Novel 2-(substituted imino)-1,3,4-dihydrothladiazoles

ABSTRACT

Novel herbicides are 3-(substituted) phenyl-2-(substituted imino)-1,3,4-dihydrothiadiazoles. Also disclosed are intermediates for such compounds, and processes for producing the herbicidal compounds and their intermediates.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No. 077,477, filed Jul. 24, 1987, now abandoned.

This invention relates to novel herbicidal compounds of the dihydrothiadiazole type, having the formula ##STR1## in which R is halo, trihalomethyl, pentahaloethyl, mono- or difluoromethyl, mono-, di-, tri- or tetrafluoroethyl, fluoroalkylthio, fluoroalkoxy, methylthio, methylsulfonyl, halomethylsulfonyl, C₁ -C₂ alkyl, or methoxy;

n is 0, 1 or 2, provided that:

(a) if n is 1 and R is other than fluoro, the substituent R is located at the 3-position on the phenyl ring; and

(b) if n is 2, the substituents R are located at the 3- and 4-positions on the phenyl ring;

R₁ is hydrogen, C₁ -C₃ alkyl, C₁ -C₃ alkoxy, C₁ -C₂ alkylthio, C₃ -C₄ alkenylthio, C₁ -C₄ alkylsulfonyl, C₁ -C₄ alkylsulfinyl, cyano, carbamyl, C₁ -C₄ mono-alkylcarbamyl, C₁ -C₂ carboalkoxy, or NR₃ R₄ in which R₃ and R₄ are independently hydrogen, C₁ -C₄ alkyl or C₂ -C₄ alkenyl; and

R₂ is phenyl; mono- or disubstituted phenyl in which the substituents are selected from halo, cyano, and trihalomethyl; C₁ -C₄ mono- or dialkylcarbamyl; phenylcarbamyl; C₁ -C₄ mono-alkylthiocarbamyl; C₄ -C₆ ketoalkenyl; cyano; C₁ -C₄ alkylsulfonyl; C₁ -C₄ haloalkylsulfonyl; or ##STR2## in which Y is oxygen or sulfur; m is 0 or 1; and R₅ is C₁ -C₁₀ alkyl; C₂ -C₁₀ alkenyl; C₂ -C₈ alkynyl if m is 0; C₃ -C₈ alkynyl in which the triple bond is separated from the oxygen or sulfur atom (Y) by at least one methylene group if m is 1; C₁ -C₈ haloalkyl if m is 0; C₂ -C₈ haloalkyl if m is 1; C₂ -C₁₀ alkoxyalkyl if m is 0; pyridyl if m is 0; C₃ -C₁₀ alkoxyalkyl in which the alkylene portion has at least two carbon atoms if m is 1; or R₅ is

    (R.sub.6).sub.p R.sub.7

in which p is 0 or 1, R₆ is a C₁ -C₂ alkylene group and R₇ is phenyl, halo-substituted phenyl; C₃ -C₇ cycloalkyl, optionally substituted by from 1 to 3 methyl groups; C₁ -C₆ carboalkoxy; or a saturated or unsaturated heterocyclic ring containing from 5 to 6 atoms including from 1 to 2 hetero atoms selected from oxygen and sulfur, optionally substituted by from 1 to 3 methyl groups and optionally substituted by from 1 to 2 oxo groups; provided that when R₁ is methylthio and R₂ is isopropylcarboxy, then R is not 2-fluoro.

In the above definition, the term "halo" includes fluoro, chloro, bromo and iodo.

When the phenyl ring shown in the basic structure is disubstituted (n=2) the two substituents may be the same or different, and are chosen from among those mentioned in the definition of the moiety R. When the phenyl ring is mono-substituted, the substituent R is preferably at the meta-position.

The term "alkyl" refers to straight and branched chain acyclic hydrocarbyl moieties having the number of carbon atoms associated with that term whenever used (i.e., by itself or as part of the definition of another moiety, e.g., "haloalkyl", "alkylthio," etc.). Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and the various pentyl, hexyl, etc. moieties. The term "iso-C₅ -H₁₁ " (isoamyl or isopentyl) designates the group 3-methylbutyl. The term "sec-C₅ -H₁₁ " designates the 2-pentyl group.

The term "carboalkoxy" refers to moieties of the specified number of carbon atoms, having the structure ##STR3## in which A represents an alkyl group, alkylalkoxy and alkylcarboalkoxy having the required number of carbon atoms. Such examples of carboalkoxy moieties include carbomethoxy, carboethoxy, 1-methyl-carbomethoxymethyl and the like.

The terms "alkylcarbamyl" and "alkylthiocarbamyl" refer respectively to moieties having the structures ##STR4## in which the nitrogen atom is further substituted by one or two alkyl groups, as defined, the alkyl groups containing the indicated number of carbon atoms. In dialkylcarbamyl compounds of this invention the two alkyl groups may be the same or different. The term "carbamyl" when used by itself refers to the unsubstituted moiety ##STR5## Examples of such substituted groups include methylcarbamyl, ethylcarbamyl, dimethylcarbamyl, N-methyl-N-ethylcarbamyl, and the like.

The term "alkenyl" refers to straight and branched chain mono- or polyunsaturated acyclic hydrocarbyl moieties with the number of carbon atoms as specified. Examples of alkenyl groups include vinyl, allyl, propenyl, isopropenyl, isobutenyl, and the like. The term "ketoalkenyl" refers to an alkenyl group in which one carbon atom is doubly bonded to an oxygen atom. One example is 3-keto-1-butenyl. The term "alkynyl" refers to straight and branched chain acyclic hydrocarbyl moieties having at least one triple bond. One example is propargyl (2-propynyl).

The term "cycloalkyl" refers to saturated cyclic hydrocarbyl moieties having the specified number of carbon atoms and includes cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

The term "haloalkyl" refers to alkyl groups or alkoxy groups having the indicated number of carbon atoms, substituted by one or more halogen atoms, which may be the same or different. When unspecified, the terms "haloalkyl" and "alkoxy" are meant to refer to alkyl groups or alkoxy groups ranging from monohalo-alkyl or monofluoroalkoxy to fully substituted halo-alkyl groups. Examples of haloalkyl and fluoroalkoxy groups include chloromethyl, dichloromethyl, difluoromethoxy, trifluoromethyl, trifluoromethxy, 2-chloroethyl, pentafluoroethyl, pentafluoroethoxy, heptafluoropropyl, heptafluoropropoxy, 3-chloropropyl, 2,2,2-trifluoro-1-methylethyl, 2,2,2-trifluoro-1-methylethoxy, 1,1,2,2-tetrafluoroethoxy and the like. The term "haloalkylsulfonyl" indicates a sulfonyl group bonded to a haloalkyl group, for instance, chloromethylsulfonyl.

The term "alkoxyalkyl" indicates an alkyl group substituted by an alkoxy group, for instance, methoxymethyl, methoxyethyl, ethoxyethyl, and the like. The indicated number of carbon atoms refers to the total number of carbon atoms in the alkoxyalkyl group (e.g., C₂ for methoxymethyl, C₃ for ethoxymethyl and the like). When R₅ is alkoxyalkyl and m is 0, the oxygen atom in the alkoxyalkyl group may be positioned anywhere in the chain. When m is 1, however, there must be at least two carbon atoms in the "alkylene" portion of the alkoxyalkyl group; that is, there must be at least two carbon atoms separating the oxygen or sulfur atom represented by the symbol "Y" and the oxygen atom of the alkoxyalkyl group (i.e., the alkoxyalkyl group is at least an alkoxyethyl group).

The value of p may be 0 or 1. When p is 0 there is a direct linkage between the group R₇ and the group ##STR6## When p is 1, R₇ and the group ##STR7## are linked by a C₁ -C₂ alkylene, e.g., methylene or 1,1-or 1,2-ethylene, group.

The heterocyclic rings included in the definition of R₇ may be saturated or may be mono-, di- or tri-unsaturated. Such rings will contain one or two oxygen or sulfur atoms, for instance, furanyl, tetrahydrofuranyl, tetrahydropyranyl, 1,3-dioxolanyl, 1,3-dioxanyl, 1,4-dioxanyl, tetrahydrothienyl, pyridyl and the like, optionally substituted with from 1 to 3 methyl groups. In addition or alternatively to the methyl substitution, the heterocyclic ring may have one or more oxygen atoms doubly bonded to carbon or sulfur atoms in the ring.

Preferred substituents are: for R_(n) --meta-halo, -trihalomethyl, fluoroalkoxy or fluoroalkylthio, particularly meta-chloro, -fluoro, -trifluoromethyl, difluoromethoxy, tetrafluoroethoxy, and -trifluoromethylthio, 3-chloro, 4-fluoro and 3-trifluoromethyl, 4-fluoro; for R₁ --alkyl (especially methyl or ethyl), alkoxy (especially methoxy), methylthio and dimethylamino; and for R₂ --4-fluorophenyl, monoalkylcarbamyl (especially methyl-, ethyl-, n-propyl- and isopropylcarbamyl), alkylcarbonyl (R₅ is alkyl, m is 0, including both straight and branched chain alkyl groups, especially C₁ -C₆ alkyl such as methyl-, ethyl-, n-propyl-, isopropyl-, isobutyl- and 2-methylbutylcarbonyl), carboalkoxy (R₅ is alkyl, m is 1, Y is oxygen, including both straight and branched chain alkyl groups, especially C₁ -C₆ alkyl such as carbomethoxy, carboethoxy, carbo-n-propoxy, carboisopropoxy, carboisobutoxy and the like), C₂ -C₈ haloalkylcarbonyl (R₅ is haloalkyl, particularly polyfluoro-C₂ -C₅ alkyl, and m is 0), C₁ -C₈ carbo-(haloalkoxy) (R₅ is haloalkyl, particularly chloro- and fluoro-C₂ -C₅ alkyl, m is 1 and Y is oxygen), optionally methyl-substituted cycloalkylcarbonyl (R₅ is (R₆)_(p) R₇, p is 0, m is 0, R₇ is cycloalkyl, particularly cyclopropyl, cyclopentyl, methylcyclopentyl or cyclohexyl), optionally methyl-substituted carbocycloalkoxy (R₅ is (R₆)_(p) R₇, p is 0, m is 1, Y is oxygen, R₇ is cycloalkyl, particularly cyclopropyl, cyclopentyl, methylcyclopentyl or cyclohexyl), optionally methyl-substituted cycloalkylmethylcarbonyl (R₅ is (R₆)_(p) R₇, p is 1, m is 0, R₆ is methylene, R₇ is as above for cycloalkyl), optionally methyl-substituted carbo-cycloalkylmethoxy (R₅ is (R₆)_(p) R₇, p is 1, m is 1, Y is oxygen, R₆ is methylene, R₇ is as above for cycloalkyl), heterocyclic carbonyl (R₅ is (R₆)_(p) R₇, p is 0, m is 0, and R₇ is a 5- or 6-member heterocyclic ring containing 1 or 2 oxygen and/or sulfur atoms, optionally substituted by from 1 to 3 methyl groups and optionally substituted by 1 or 2 oxo groups, particularly furanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxolanyl, dioxanyl, tetrahydrothienyl, tetrahydro1-oxothienyl, 2,2-dimethyl-1,3-dioxolanyl and the like), carbo-heterocyclic-oxy (R₅ is (R₆)_(p) R₇, p is 0, m is 1, Y is oxygen, and R₇ is a heterocyclic ring as described above), heterocyclic-methyl-carbonyl (p is 1, m is 0, R₆ is methylene, R₇ is heterocyclic) and carbo-(heterocyclic-methoxy) (p is 1, m is 1, Y is oxygen, R₆ is methylene and R₇ is heterocyclic).

When it is indicated that a phenyl ring may be di- or further substituted, the substituents may be the same or different, and are selected from the specified groups. When no specific position of substitution is mentioned on a phenyl ring, it is intended that the substituent or substituents may be substituted at any position on the ring.

The compounds of this invention have been found to be active herbicides, possessing pre- and/or post-emergence herbicidal activity against various types of weeds, including broadleaf and grassy weeds. As mentioned hereinbelow, some of the compounds demonstrate selective control of weeds in certain crops, such as cereals, including wheat, rice, barley, and in cotton.

This invention therefore also relates to a method for controlling undesirable vegetation comprising applying to a locus where control of such vegetation is desired, either prior or subsequent to the emergence of such vegetation, a herbicidally effective amount of a compound as described herein, and also relates to herbicidal compositions comprising a herbicidally effective amount of a compound as described herein, together with an inert diluent or carrier suitable for use with herbicides.

As used herein, the term "herbicide" refers to compounds which adversely control or modify the growth of plants, particularly of undesirable plants. By the term "herbicidally effective amount" is meant an amount of compound which causes an adverse controlling or modifying effect on the growth of plants. The term "plants" is meant to include germinant seeds, emerging seedlings, and established vegetation, including roots and above-ground portions. Such adverse modifying and controlling effects may include all deviations from natural development.

There are several processes by which the compounds of this invention may be prepared. Some of these processes, as well as intermediates, are also novel and form other aspects of this invention.

PROCESS A: Reaction of A Substituted Thionohydrazine with an Imidoyl Dihalide

In this process, the appropriate thionohydrazine is reacted with an imidoyl dihalide in the presence of a base according to the reaction: ##STR8## in which R, R₁, R₂, and n are as previously described and Hal stands for a halogen, preferably chlorine. Both halogens (Hal) are identical. This reaction is conducted at a temperature of from about -100° C. to about +150° C., preferably from about -78° C. to about +80° C. Suitable bases include trialkylamines, preferably tri-lower alkylamines such as triethylamine, pyridine, alkali metal hydrides (preferably sodium hydride) and alkali metal tertiary alkoxides such as sodium and potassium tertiary butoxides. The reaction may be carried out in the presence of a solvent. Suitable solvents include dimethylformamide, tetrahydrofuran, 1,2-dichloroethane, and benzene.

This method is the preferred process for the production of arylimino compounds (R₂ is phenyl or substituted phenyl), but may be used for production of all compounds of this invention.

The starting materials for this process are readily available. The imidoyl dihalides may be prepared according to the literature, for instance by reaction of formanilides with thionyl chloride and sulfuryl chloride. The thionohydrazines are prepared as described below.

All intermediates and final products in the examples which follow, as well as those which appear subsequently, were identified by typical spectroscopic methods, including nuclear magnetic resonance, infrared and mass spectroscopy.

The following are examples of production of compounds by process A.

EXAMPLE 1 Preparation of 2-(4-Fluorophenyl)imino-3-(3-trifluoromethyl)phenyl-5-methoxy-2,3-dihydro-1,3,4-thiadiazole (Compound 99 herein)

(a) Production of the Thionohydrazine

In a 100 milliliter (ml) flask were placed 6.5 grams (g) (0.03 mole) of 25% sodium methoxide and 2.3 g (0.03 mole) of carbon disulfide. This mixture was stirred 20 minutes and 10 ml water and 3.5 g (0.03 mole) of chloroacetic acid sodium salt were added and stirred one hour. Most of the solvent was then removed under vacuum and replaced with 10 ml methanol and 4.4 g (0.025 mole) (3-trifluoromethyl)phenyl hydrazine. This mixture was then heated on a steam bath for 0.5 hour and the solvent stripped. The residue was dissolved in ether, washed with water, phase separated, dried and stripped to yield 5 g of solids.

(b) In a 100 ml flask were placed 2.5 g (0.01 mole) of the intermediate obtained in step (a), 15 ml of 1,2-dichloroethane, and 1.9 g (0.01 mole) of 4-fluorophenyl imidoyl dichloride. This stirred solution was cooled in an ice bath and 2.8 ml (0.02 mole) of triethylamine added. The mixture was stirred cold 0.5 hour then refluxed 0.5 hour. The solution was washed with water, phase separated, dried and stripped. The residue was treated with 50 ml of hot hexane, decanted and allowed to cool. The solids were collected to yield 2.2 g (m.p. 113°-115° C.) identified as the expected product.

PROCESS B:

Compounds of this invention in which R₂ is C₁ -C₄ alkylcarbamyl, phenylcarbamyl, alkylthiocarbamyl, cyano, ketoalkenyl, alkylsulfonyl, haloalkylsulfonyl, or ##STR9## in which Y, m and R₅ are as defined above, may be prepared by a two-step process represented by the scheme: ##STR10##

In the first step of this process, a 2-imino-3-(substituted) phenyl thiadiazole is prepared by cyclization of a phenyl thionohydrazine having the formula ##STR11## with a cyanogen halide having the formula Z-CN in which Z is chloro or bromo. The cyclization reaction is conducted in the presence of an inert solvent such as diethyl ether, a chlorinated hydrocarbon solvent (e.g., methylene chloride, chloroform or 1,2-dichloroethane) or a hydrocarbon solvent such as toluene. Temperatures may range from about -50° C. to about +150° C., and are preferably from about 0° C. to about 25° C. The process when carried out in this manner produces the hydrohalide product of the intermediate iminothiadiazole, which is indicated by the use of the term "(·HZ)" in the above equation. In an alternative embodiment this cyclization reaction may be run in the presence of a suitable base such as sodium hydride or a tertiary amine to produce the free iminothiadiazole intermediate, or the free intermediate may be produced by neutralization of the hydrohalide salt at the completion of the reaction. The iminothiadiazole intermediates, and their hydrohalide salts are novel, and may also have herbicidal activity. The iminothiadiazoles correspond to the general formula ##STR12## in which R, n and R₁ are as previously defined and R₂ is hydrogen.

In the second step of this process the intermediate iminothiadiazole compound (as the free compound or the hydrohalide salt) is reacted with the appropriate acylating agent in the presence of a suitable base. If the desired product is one in which R₂ has the formula ##STR13## the acylating agent has the formula ##STR14## in which Z' is a halogen, preferably chloro, bromo or iodo. If the desired product is one in which R₂ is C₁ -C₄ alkylcarbamyl, C₁ -C₄ alkylthiocarbamyl or phenylcarbamyl, the acylating agent is the appropriate isocyanate or isothiocyanate (R₉ NCO or R₉ NCS in which R₉ is C₁ -C₄ alkyl or phenyl). If the iminothiadiazole intermediate is used in the form of its hydrohalide salt, one molar equivalent of the base is required. Suitable bases include amines, sodium hydroxide and sodium bicarbonate. This acylation reaction may be carried out in the presence of a solvent typically used for acylation reactions, for instance, toluene, methylene chloride or diethyl ether. The temperature of the acylation reaction may be from about -50° C. to about +150° C., preferably from about 0° C. to about 25° C.

The substituted phenyl thiono hydrazines ##STR15## in which n=1 or 2 are also novel. They may be prepared in several ways, depending on the definition of R₁.

Thiono hydrazines in which R₁ is alkylthio or alkenylthio can be prepared by reaction of a substituted phenyl hydrazine with carbon disulfide in the presence of a base and an alkylating agent such as an alkyl or alkenyl halide (iodide, chloride or bromide), sulfate, etc. This reaction is conducted at a temperature generally from about -50° C. to about +150° C., preferably from about 0° C. to about 25° C. The solvent may be used which is inert to the reactants or product, for example, diethyl ether, tetrahydrofuran, toluene or benzene. The base is preferably a weak base such as a trialkylamine, pyridine, or potassium carbonate.

Thiono hydrazines in which R₁ is alkoxy may be prepared by reaction of the appropriate substituted phenyl hydrazine with a dithiocarbonate ##STR16## in which R₁ is C₁ -C₃ alkoxy and R₈ is a C₁ -C₄ alkyl or methylcarboxy group. This reaction is again carried out at temperatures of from about -50° C. to about +150° C., preferably from about 80° C. to about 110° C. The reaction may be run with or without solvent. If run with a solvent, inert solvents such as toluene, tetrahydrofuran, alcohol or alcohol-water mixtures may be employed. The dithiocarbonate may be produced by reaction of an alkali metal alkoxide with carbon disulfide in the presence of an alkylating agent which introduces the group R₈. This reaction can be carried out in neat alcohol, ethereal solvents such as tetrahydrofuran or dimethyl ether or other inert solvents, for instance dimethylformamide. The temperature may be from about -50° C. to about +150° C., preferably from about 60° C. to about 80° C. The group R₈ is preferably one which is readily replaced as R.sub. 8 S- at a later step in the overall process. Consequently, R₈ is preferably a small group or groups such that the overall group R₈ SH is a good leaving group and is either volatile or water soluble.

Thiono hydrazine in which R₁ is a C₁ -C₃ alkyl group are preferably made by reaction of the appropriate substituted phenyl hydrazide with phosphorus pentasulfide. Temperature of the reaction is from about -50° C. to about +150° C., preferably from about 80° C. to about 110° C. This reaction may be carried out in the presence of an inert solvent, for instance benzene, toluene, xylene or dioxane.

Thiono hydrazines in which R₁ is NR₃ R₄ may be prepared from the thiono hydrazines in which R₁ is thioalkyl by reaction with an appropriate amine. This process is carried out in the presence of a solvent, preferably an alcoholic solvent, but optionally another solvent such as dimethylformamide, toluene, or 1,2-dichloroethane. The temperature of this reaction is from about -50° C. to about +150° C., preferably from about 80° C. to about 110° C.

The following represent examples of processes of type B.

EXAMPLE 2 Preparation of 2-(Acetyl)imino-3-(3-trifluoromethyl)phenyl-5-methylthio-2,3-dihydro-1,3,4-thiadiazole (Compound 44 herein)

(a) Production of Thiono hydrazine

In a one liter flask were placed 200 ml of toluene, 14 ml of triethylamine (0.1 mole) and 17.6 g of (3-trifluoromethyl)phenyl hydrazine (0.1 mole). This solution was cooled in an ice bath and 10 ml of carbon disulfide (0.167 mole) was added rapidly but dropwise. This solution was stirred one hour, then 10 ml of dimethyl sulfate (0.106 mole) was added rapidly but dropwise (there was a slight exotherm). The mixture was stirred overnight at ambient temperature. To this mixture was added 250 ml water and 200 ml of diethyl ether. The reaction was separated, dried over magnesium sulfate and the ether removed at reduced pressure to yield solids which were washed in pentane to yield 17.2 g of solids (m.p. 148°-149° C.).

(b) Cyclization to Iminothiadizole intermediate

In a 250 ml flask were placed 8.0 g (0.03 mole) of the product of step (a) and 50 ml of toluene. This was cooled in an ice bath and 4.1 g of cyanogen bromide (0.04 mole) in 50 ml of toluene added. The mixture was stirred several hours at ambient temperature. The solids were collected by filtration to yield 7.1 g.

(c) Acylation

In a 100 ml flask were placed 3.7 g of the solid just obtained (0.01 mole), 20 ml of methylene chloride and 0.8 ml of acetyl chloride (0.011 mole). This solution was then cooled in an ice bath and 2.2 ml of pyridine (0.022 mole) was added dropwise. The solution was stirred one hour and worked up in the usual manner to yield 3.2 g of solids, m.p. 95°-97° C.

EXAMPLE 3 Preparation of 2-(Carboethoxy)imino-3-(3-trifluoromethyl)phenyl-5-dimethylamino-2,3-dihydro-1,3,4-thiadiazole (Compound 82 herein)

(a) Preparation of Thiono hydrazine

In a one liter flask were placed 50.5 g (0.19 mole) of 1-methyldithiocarbonyl-2-(3-trifluoromethyl)phenyl hydrazine (prepared as in Example 2a), 350 ml of ethanol and 83 ml (0.6 mole) of 40% aqueous dimethylamine. The solution was refluxed for 5 hours and the solvent stripped. The solids were washed with ether to collect 33.9 g of solids, m.p. 162°-168° C.

(b) Cyclization

In a 500 ml flask were placed 11.9 g (0.045 mole) of the product from above and 120 ml of toluene. This solution was then cooled in an ice bath and 5.3 g (0.05 mole) of cyanogen bromide in 40 ml of toluene was added dropwise. The slurry was stirred overnight and filtered to collect 15.7 g of the solid hydrobromide salt.

(c) Acylation

In a 100 ml flask were placed 3.4 g (0.009 mole) of the solids obtained in step (b), 20 ml of methylene chloride and 1.0 ml of ethyl chloroformate (0.01 mole). This mixture was cooled in an ice bath and 1.6 ml (0.02 mole) of pyridine dissolved in 5 ml dichloromethane added dropwise with stirring. The mixture was stirred 1 hour and washed with water, separated, dried and stripped to yield 3.2 g of solids (m.p. 92°-93° C.), identified as the expected product.

EXAMPLE 4 Preparation of 2-(Carboisopropoxy)imino-3-(3-trifluoromethyl)phenyl-5-ethoxy-2,3-dihydro-1,3,4-thiadiazole (Compound 83 herein)

(a) Preparation of dithiocarbonate

In a 500 ml flask were placed 100 ml of ethanol and 24 g (0.3 mole) of 50% sodium hydroxide. To this stirred solution was added 21 ml (0.35 mole) of carbon disulfide dropwise. This solution was stirred 0.5 hour and 33 ml (0.35 moles) of dimethyl sulfate was added dropwise. The mixture was stirred overnight at ambient temperature. The ethanol was stripped and the residue taken up in ether, washed with water, dried and stripped to yield 34 g.

(b) Preparation of Thiono hydrazine

In a 200 ml flask were placed 8 g (0.06 mole) of the product of step (a) and 8.8 g (0.05 mole) of (3-trifluoromethyl)phenyl hydrazine. The solution was heated on a steam bath for 5 hours then stripped to remove low boilers, yielding 15.2 g of a thick oil.

(c) Cyclization

The product of step (a) was dissolved in 150 ml of toluene and 6.1 g (0.06 mole) of cyanogen bromide added in one portion. This mixture was stirred overnight and filtered to collect 7 g of solid hydrobromide.

(d) Acylation

In a 100 ml flask were placed 3.5 g (0.01 mole) of the product of step (c), 20 ml of methylene chloride and 1.2 ml (0.011 mole) of isopropyl chloroformate. This mixture was stirred and cooled in an ice bath, and 1.7 ml (0.21 mole) of pyridine in 5 ml methylene chloride was added dropwise. The mixture was stirred one hour and worked up in the usual manner to yield 3.3 g of solid, m.p. 105°-111° C., identified as the expected product.

EXAMPLE 5 Preparation of 2-(Carbo-n-propoxy)imino-3-(3-trifluoromethyl)phenyl-5-ethyl-2,3-dihydro-1,3,4-thiadiazole (Compound 117 herein)

(a) Preparation of Thiono hydrazine

In a 2 liter flask were placed 50 g (0.28 mole) of (3-trifluoromethyl)phenyl hydrazine, 250 ml methylene chloride, 250 ml of 20% sodium hydroxide and 250 g of ice. The stirred mixture was cooled in an ice bath and 25 ml (0.28 mole) of propionyl chloride added dropwise. After addition, this mixture was stirred one hour, phase separated, dried over magnesium sulfate and the organics stripped to collect 54 g solids. In a one liter flask was placed 25 g (0.11 mole) of the solids just obtained and 350 ml benzene. With stirring, 50 g of P₄ S₁₀ was added and the slurry heated to reflux for 0.25 hour. Twenty ml of water was then carefully added, followed by another 350 ml of water. The mixture was refluxed until the solids all dissolved, then cooled and phase separated. The organic layer was dried, and the solvent stripped to yield 29 g of the expected intermediate.

(b) Cyclization

This material (0.12 mole) was then dissolved in 125 ml of toluene and cooled in an ice bath. With stirring was added 8 (0.13 mole) of cyanogen chloride in 30 ml of toluene. The mixture was stirred overnight at ambient temperature, then filtered to yield 11 g of solid hydrochloride.

(c) Acylation

In a 100 ml flask were placed 3.7 g (0.012 mole) of the product of step (b), 15 ml methylene chloride and 1.5 ml (0.013 mole) n-propyl chloroformate. The stirred mixture was cooled in an ice bath and 2.1 ml (0.026 mole) of pyridine added dropwise. The mixture was stirred one hour, washed with water and phase separated. The organics were dried and stripped to yield 3.0 g solids (m.p. 53°-56° C.), identified as the expected product.

OTHER PROCESSES

Herbicidal compounds in which R₁ is alkylsulfinyl or alkylsulfonyl are prepared by oxidation of corresponding compounds in which R₁ is alkylthio, under conventional conditions for such oxidations.

Herbicidal compounds in which R₁ is cyano, carbamyl or mono-alkylcarbamyl are prepared through the corresponding dihydrothiadiazoles in which R₁ is C₁ -C₂ carboalkoxy. These are prepared using process B. The thiono hydrazines in which R₁ is C₁ -C₂ carboalkoxy are prepared by reacting the appropriate phenyl hydrazine with methyl or ethyl oxalyl chloride or dimethyl or diethyl oxalate, then reacting the product with phosphorus pentasulfide, as in production of thiono hydrazines in which R₁ is an alkyl group.

The herbicidal compounds in which R₁ is carbamyl or C₁ -C₄ mono-alkylcarbamyl are prepared by reacting those compounds in which R₁ is carboalkoxy with ammonia or a mono-alkyl amine, respectively. Compounds in which R₁ is cyano are prepared by dehydration of the corresponding carbamyl compounds under conventional conditions.

The compounds in which R₁ is C₁ -C₂ carboalkoxy are useful as intermediates for preparation of the corresponding cyano, carbamyl or mono-alkylcarbamyl ones.

The following Table I depicts representative compounds of this invention.

                                      TABLE I                                      __________________________________________________________________________     Thiadiazoles                                                                    ##STR17##                                                                     Cmpd. No.                                                                             R       R.sub.1  R.sub.2              m.p. °C. or                                                             n.sub.D.sup.30                    __________________________________________________________________________     1      3-CF.sub.3                                                                             NHCH.sub.3                                                                              3-CF.sub.3C.sub.6 H.sub.4                                                                           oil                               2      3-CF.sub.3                                                                             NHCH.sub.3                                                                              4-FC.sub.6 H.sub.4   semi-solid                        3      3-CF.sub.3                                                                             NHCH.sub.3                                                                              4-ClC.sub.6 H.sub.4  semi-solid                        4      3-CF.sub.3                                                                             NHCH.sub.3                                                                              4-BrC.sub.6 H.sub.4  semi-solid                        5      3-CF.sub.3                                                                             NHCH.sub.3                                                                              3,4-ClC.sub.6 H.sub.3                                                                               semi-solid                        6      3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       4-FC.sub.6 H.sub.4   105-110                           7      3-CF.sub.3                                                                             SCH.sub.3                                                                               4-FC.sub.6 H.sub.4   105-110                           8      3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       3-CF.sub.3C.sub.6 H.sub.4                                                                           85-94                             9      3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       4-BrC.sub.6 H.sub.4  140-146                           10     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       3,4-ClC.sub.6 H.sub.3                                                                               103-110                           11     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       4-ClC.sub.6 H.sub.4  129-137                           12     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       4-CNC.sub.6 H.sub.4  166-168                           13     3-CF.sub.3                                                                             SCH.sub.3                                                                               3-CF.sub.3C.sub.6 H.sub.4                                                                           95-98                             14     3-CF.sub.3                                                                             SCH.sub.3                                                                               4-BrC.sub.6 H.sub.4  125-129                           15     3-CF.sub.3                                                                             SCH.sub.3                                                                               3,4-ClC.sub.6 H.sub.3                                                                               66-75                             16     3-CF.sub.3                                                                             SCH.sub.3                                                                               4-ClC.sub.6 H.sub.4  114-124                           17     3-CF.sub.3                                                                             SCH.sub.3                                                                               4-CNC.sub.6 H.sub.4  128-135                           18     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            126-127                           19     3-CF.sub.3                                                                             SCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               87-90                             20     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              75-78                             21     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       COO-i-C.sub.3 H.sub.7                                                                               130-133                           22     3-CF.sub.3                                                                             SCH.sub.3                                                                               COOC.sub.2 H.sub.5   59-62                             23     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)S-i-C.sub.3 H.sub.7                                                                             57-62                             24     3-CF.sub.3                                                                             SCH.sub.3                                                                                ##STR18##           60-64                             25     3-CF.sub.3                                                                             SCH.sub.3                                                                               COO-i-C.sub.4 H.sub.9                                                                               1.5770                            26     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)NHCH.sub.3       113-116                           27     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)-i-C.sub.3 H.sub.7                                                                              85-87                             28     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)SC.sub.2 H.sub.5 73-79                             29     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)NH-n-C.sub.3 H.sub.7                                                                            111-113                           30     3-CF.sub.3                                                                             C.sub.2 H.sub.5                                                                         COO-i-C.sub.3 H.sub.7                                                                               69-72                             31     3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               98-100                            32     3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            163-165                           33     3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              35-38                             34     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       C(O)-i-C.sub.4 H.sub.9                                                                              1.5637                            35     3-CF.sub.3                                                                             SC.sub.2 H.sub.5                                                                        C(O)S-i-C.sub.3 H.sub.7                                                                             oil                               36     3-CF.sub.3                                                                             SC.sub.2 H.sub.5                                                                        C(O)NH-i-C.sub.3 H.sub.7                                                                            135-138                           37     3-CF.sub.3                                                                             SC.sub.2 H.sub.5                                                                        COO-i-C.sub.3 H.sub.7                                                                               78-81                             38     3-CF.sub.3                                                                             SC.sub.2 H.sub.5                                                                        C(O)-i-C.sub.4 H.sub.9                                                                              semi-solid                        39     3-CF.sub.3                                                                             SC.sub.2 H.sub.5                                                                        C(O)-n-C.sub.3 H.sub.7                                                                              54-58                             40     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       C(O)NH-i-C.sub.3 H.sub.7                                                                            160-162                           41     3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)S-i-C.sub.3 H.sub.7                                                                             52-60                             42     3-CF.sub.3                                                                             OCH.sub.3                                                                               COOC(CH.sub.3)CH.sub.2                                                                              86-90                             43     3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CHC(CH.sub.3).sub.2                                                                             107-111                           44     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)CH.sub.3         95-97                             45     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)CHC(CH.sub.3).sub.2                                                                             99-100                            46     3-CF.sub.3                                                                             SCH.sub.3                                                                                ##STR19##           94-96                             47     3-CF.sub.3                                                                             SCH.sub.3                                                                               COOC(CH.sub.3)CH.sub.2                                                                              90-96                             48     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)NHC.sub.2 H.sub.5                                                                               78-84                             49     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       C(O)S-i-C.sub.3 H.sub.7                                                                             98-102                            50     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       C(O)CHC(CH.sub.3).sub.2                                                                             118-121                           51     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)-i-C.sub.5 H.sub.11                                                                             1.6324                            52     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)CH.sub.2 CH(CH.sub.3)C.sub.2 H.sub.5                                                            107-111                           53     3-CF.sub.3                                                                             SCH.sub.3                                                                                ##STR20##           48-52                             54     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)-n-C.sub.3 H.sub.7                                                                              45-48                             55     3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)CH.sub.2 CH(CH.sub.3)CF.sub.3                                                                   1.5855                            56     3-Cl    SCH.sub.3                                                                               C(O)-i-C.sub.3 H.sub.7                                                                              wax                               57     3-Cl    SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              1.6290                            58     3-Cl    SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            wax                               59     3,4-Cl  SCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               98-101                            60     3,4-Cl  SCH.sub.3                                                                               COO-i-C.sub.4 H.sub.9                                                                               wax                               61     3,4-Cl  SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            125- 128                          62     3-F     SCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               wax                               63     3-F     SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              wax                               64     3-F     SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            wax                               65     2-F     SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              wax                               66     2-F     SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            140-144                           67     4-F     SCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               wax                               68     4-F     SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              1.6000                            69     4-F     SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            124-126                           70     3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH.sub.3          126-129                           71     3-CF.sub.3                                                                             OCH.sub.3                                                                               COOC.sub.2 H.sub.5   84-87                             72     3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-n-C.sub.3 H.sub.7                                                                               49-52                             73     3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-i-C.sub.4 H.sub.9                                                                               43-47                             74     3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-n-C.sub.5 H.sub.11                                                                              1.5454                            75     3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-n-C.sub.4 H.sub.9                                                                               43-47                             76     3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH.sub.2 CHCH.sub.3                                                                              60-76                             77     3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-sec-C.sub.5 H.sub.11                                                                            41-46                             78     3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-sec-C.sub.4 H.sub.9                                                                             85-87                             79     3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH.sub.2 CH.sub.2 Cl                                                                             66-69                             80     3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH.sub.2 CH.sub.2 OCH.sub.3                                                                      55-59                             81     3-CF.sub.3                                                                             N(CH.sub.3 ).sub.2                                                                      COO-sec-C.sub.4 H.sub.9                                                                             129-131                           82     3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       COOC.sub.2 H.sub.5   92-93                             83     3-CF.sub.3                                                                             OC.sub.2 H.sub.5                                                                        COO-i-C.sub.3 H.sub.7                                                                               105-111                           84     3-CF.sub.3                                                                             OC.sub.2 H.sub.5                                                                        C(O)-i-C.sub.4 H.sub.9                                                                              semi-solid                        85     3-SCF.sub.3                                                                            OCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               1.5485                            86     3-SCF.sub.3                                                                            OCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              39-46                             87     3-CF.sub.3                                                                             N(CH.sub.3)n-C.sub.3 H.sub.7                                                            COO-i-C.sub.3 H.sub.7                                                                               75-85                             88     3-CF.sub.3                                                                             N(CH.sub.3)n-C.sub.3 H.sub.7                                                            C(O)-i-C.sub.4 H.sub.9                                                                              1.5375                            89     3-SCF.sub.3                                                                            SCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               80-84                             90     3-SCF.sub.3                                                                            SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              45-48                             91     3-Cl    OCH.sub.3                                                                               COO-i-C.sub.3 H.sub.7                                                                               68-72                             92     3-Cl    OCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              1.5790                            93     3-Cl    OCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            119-121                           94     3-Cl    OCH.sub.3                                                                               C(O)-S-i-C.sub.3 H.sub.7                                                                            77-81                             95     3-Cl    OCH.sub.3                                                                               COOC.sub.2 H.sub.5   121-123                           96     3-Cl    OCH.sub.3                                                                               COO-sec-C.sub.4 H.sub.9                                                                             50-59                             97     3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH(C.sub.2 H.sub.5).sub.2                                                                        66-73                             98     3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR21##           94-97                             99     3-CF.sub.3                                                                             OCH.sub.3                                                                               4-F-C.sub.6 H.sub.5  113-115                           100    3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       C(O)CH.sub.2 CH(CH.sub.3)CF.sub.3                                                                   61-64                             101    3-Cl    OCH.sub.3                                                                               C(O)CH.sub.2 CH(CH.sub.3)CF.sub.3                                                                   69-71                             102    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CH.sub.3         76-80                             103    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)C.sub.2 H.sub.5  semi-solid                        104    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)-n-C.sub.3 H.sub.7                                                                              1.5402                            105    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)-i-C.sub.5 H.sub.11                                                                             1.5243                            106    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CH.sub.2 CH(CH.sub.3)CF.sub.3                                                                   52-54                             107    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CH.sub.2 CH.sub.2 CH.sub.2 Cl                                                                   38-39                             108    3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH.sub.2 CCl.sub.3                                                                               73-79                             109    3-CF.sub.3                                                                             OCH.sub.3                                                                               COOC.sub.6 H.sub.5   128-133                           110    3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-n-C.sub.6 H.sub.13                                                                              1.5181                            111    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)-sec-C.sub.5 H.sub.11                                                                           1.5307                            112    3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH.sub.2 C.sub.5 H.sub.5                                                                         93-100                            113    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CF.sub.2 CF.sub.2 CF.sub.3                                                                      65-67                             114    3-CF.sub.3                                                                             OCH.sub.3                                                                               SO.sub.2 -n-C.sub.3 H.sub.7                                                                         semi-solid                        115    3-CF.sub.3                                                                             C.sub.2 H.sub.5                                                                          ##STR22##           94-96                             116    3-CF.sub.3                                                                             C.sub.2 H.sub.5                                                                         C(O)-i-C.sub.4 H.sub.9                                                                              1.5210                            117    3-CF.sub.3                                                                             C.sub.2 H.sub.5                                                                         COO-n-C.sub.3 H.sub.7                                                                               53-56                             118    3-CF.sub.3                                                                             C.sub.2 H.sub.5                                                                         COO-i-C.sub.4 H.sub.9                                                                               1.5250                            119    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR23##           1.5340                            120    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR24##           1.5348                            121    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR25##           82.88                             122    3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                        ##STR26##           122-124                           123    3-CF.sub.3                                                                             SCH.sub.3                                                                               C(O)NHC.sub.6 H.sub.5                                                                               161-163                           124    3-CF.sub.3                                                                             NHCH.sub.3                                                                              COO-i-C.sub.3 H.sub.7                                                                               141-156                           125    3-CF.sub.3                                                                             CH.sub.3 COO-i-C.sub.3 H.sub.7                                                                               113-118                           126    3-CF.sub.3                                                                             CH.sub.3 C(O)-i-C.sub.4 H.sub.9                                                                              waxy solid                        127    3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH(CH.sub.3)CH(CH.sub.3).sub.2                                                                   85-88                             128    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR27##           1.5365                            129    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR28##           94-95                             130    3-CF.sub.3                                                                             OCH.sub.3                                                                               CN                   83-86                             131    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CH.sub.2 COOC.sub.2 H.sub.5                                                                     50-54                             132    3-CF.sub.3                                                                             OCH.sub.3                                                                               SO.sub.2 CH.sub.2 Cl 102-105                           133    3-CF.sub.3                                                                             CN       COO-i-C.sub.3 H.sub.7                                                                               93-96                             134    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(S)NHCH.sub.3       150-154                           135    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR29##           83-87                             136    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR30##           63-70                             137    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR31##           84-86                             138    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)NHCH.sub.3       119-122                           137    3-CF.sub.3                                                                             OCH.sub.3                                                                               CHCHC(O)CH.sub.3     79-81                             140    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)N(CH.sub.3).sub.2                                                                                9-103                            141    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR32##           79-81                             142    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR33##           89-97                             143    3-CF.sub.3                                                                             N(CH.sub.3).sub.2                                                                       COO-i-C.sub.3 H.sub.7                                                                               57-64                             144    3-CF.sub.3                                                                             C(O)NH.sub.2                                                                            COO-i-C.sub. 3 H.sub.7                                                                              186-195                           145    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR34##           1.5332                            146    3-CF.sub.3                                                                             OCH.sub.3                                                                               COO-t-C.sub.4 H.sub.9                                                                               113-118                           147    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR35##           55-59                             148    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR36##           95-91                             149    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR37##           112-113                           150    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR38##            79-90.5                          151    3-CF.sub.3                                                                             OCH.sub.3                                                                               COOCH(CH.sub.3)COOCH.sub.3                                                                          97-99                             152    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CH.sub.2 Cl      65-68                             153    3-CF.sub.3                                                                             OCH.sub.3                                                                               SO.sub.2 CH.sub.3    114-115                           154    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR39##           140-141                           155    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR40##           105-106                           156    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR41##           61-65                             157    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR42##           149-151                           158    3-CF.sub.3                                                                             C(O)NHCH.sub.3                                                                          C(O)O-i-C.sub.3 H.sub.7                                                                             196.5-200.5                       159    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR43##           160.3-163.6                       160    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR44##           136.2-137.9                       161    3-CF.sub.3                                                                             OCH.sub.3                                                                               C(O)CH.sub.2 OCH.sub.3                                                                              61.8-64.1                         162    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR45##           99.6-100.6                        163    3-CF.sub.3                                                                             SO.sub.2 CH.sub.3                                                                       C(O)CH.sub.2 CH(CH.sub.3).sub.2                                                                     121.6-123.7                       164    H       SCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             101.3-103.9                       165    H       SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              1.6055                            166    H       SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            120.5-123.8                       167    3-CH.sub.3                                                                             SCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             1.6053                            168    3-CH.sub.3                                                                             SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              oil                               169    3-CH.sub.3                                                                             SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            74.4-79.7                         170    3-OCH.sub.3                                                                            SCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             oil                               171    3-OCH.sub.3                                                                            SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            109.9-111.8                       172    3-CF.sub.3                                                                             SCH.sub.3                                                                                ##STR46##           100.6-107.8                       173    3-CF.sub.3                                                                             SCH.sub.3                                                                                ##STR47##           72.6-75.8                         174    3-CF.sub.3, 4-F                                                                        SCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             105.5-107.7                       175    3-CF.sub.3, 4-F                                                                        SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              42.9-51.0                         176    3-CF.sub.3, 4-F                                                                        SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            135.8-136.5                       177    3-SCH.sub.3                                                                            SCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             1.5275                            178    3-SCH.sub.3                                                                            SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            semi-solid                        179    3-Cl, 4-F                                                                              SCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             110.8-112.8                       180    3-Cl, 4-F                                                                              SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              52.6-55.9                         181    3-Cl, 4-F                                                                              SCH.sub.3                                                                               C(O)NH-i-C.sub.3 H.sub.7                                                                            81.3-92.8                         182    3-CF.sub.3                                                                             S(O)CH.sub.3                                                                            C(O)-i-C.sub.4 H.sub.9                                                                              86.2-92.1                         183    3-SCH.sub.3                                                                            OCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             1.5436                            184    3-Cl, 4-F                                                                              OCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              49.0-59.2                         185    3-Cl, 4-F                                                                              OCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             127.3-129.0                       186    3-Cl, 4-F                                                                              OCH.sub.3                                                                                ##STR48##           125.9-127.4                       187    3-SO.sub.2 CH.sub.3                                                                    OCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             144.5-146.2                       188    3-CF.sub.3, 4-F                                                                        OCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             98.6-101.0                        189    3-CF.sub.3, 4-F                                                                        OCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              54.9-58.0                         190    3-CF.sub.3, 4-F                                                                        OCH.sub.3                                                                                ##STR49##           106.1-109.8                       191    3-CF.sub.3                                                                             SCH.sub.3                                                                                ##STR50##           132.0-136.0                       192    3-OCF.sub.3                                                                            OCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             light oil                         193    3-OCF.sub.2 H                                                                          OCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             1.5485                            194    3-OCF.sub.2 CF.sub.2 H                                                                 SCH.sub.3                                                                                ##STR51##           79.7-82.8                         195    3-OCF.sub.2 CF.sub.2 H                                                                 SCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             82.5-85.7                         196    3-OCF.sub.2 CF.sub.2 H                                                                 SCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              57.4-62.9                         197    3-OCF.sub.2 CF.sub.2 H                                                                 OCH.sub.3                                                                               C(O)O-i-C.sub.3 H.sub.7                                                                             88.6-89.4                         198    3-OCF.sub.2 CF.sub.2 H                                                                 OCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              81.4-83.8                         199    3-OCF.sub.2 CF.sub.2 H                                                                 OCH.sub.3                                                                               C(O)-i-C.sub.4 H.sub.9                                                                              50.0-51.8                         200    3-OCF.sub.2 CF.sub.2 H                                                                 OCH.sub.3                                                                                ##STR52##           1.5410                            201    3-OCF.sub.2 CF.sub.2 H                                                                 OCH.sub.3                                                                                ##STR53##           80.9-90.6                         202    3-OCF.sub.2 CF.sub.2 H                                                                 OCH.sub.3                                                                                ##STR54##           1.5330                            203    3-CF.sub.3 -4-F                                                                        OCH.sub.3                                                                                ##STR55##            99.7-102.4                       204    3-CF.sub.3 -4-F                                                                        OCH.sub.3                                                                                ##STR56##           108.9-111.4                       205    3-CF.sub. 3 -4-F                                                                       OCH.sub.3                                                                                ##STR57##           89.6-92.2                         206    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR58##           79.7-81.8                         207    3-CF.sub.3                                                                             OCH.sub.3                                                                                ##STR59##           1.5524                            208    3-CF.sub.3                                                                             OC.sub.2 H.sub.5                                                                        C(O)OC.sub.2 H.sub.5 88.4-92.4                         209    3-CF.sub.3                                                                             OC.sub.2 H.sub.5                                                                        C(O)C.sub.3 H.sub.7  semi-solid                        210    3-CF.sub.3                                                                             OC.sub.2 H.sub.5                                                                         ##STR60##           78.8-80.2                         211    3-CF.sub.3                                                                             OC.sub.2 H.sub.5                                                                         ##STR61##           104.9-107.0                       212    3-CF.sub.3                                                                             H        C(O)-i-C.sub.3 H.sub.7                                                                              thick oil                         Iminothiadiazole Intermediates                                                 213    3-CF.sub.3                                                                             OCH.sub.3                                                                               --                      72-73.5                        214    hydrobromide of compound No. 191       144-145                          215    3-CF.sub.3                                                                             SCH.sub.3                                                                               hydrobromide          222.3-224.2                      __________________________________________________________________________      *Produced as a mixture due to mixture of isomers in starting materials.  

HERBICIDAL EVALUATION

Compounds of the foregoing Table I were tested for herbicidal activity as follows.

PRE-EMERGENCE HERBICIDE SCREENING TEST

Flats were filled with sandy loam soil containing a fungicide and fertilizer. The soil was leveled and rows of three grassy weeds, three broadleaf weeds and yellow nutsedge (Cyperus esculentus), were planted thickly enough so that several seedlings emerged per inch of row. The grassy weeds were: green foxtail (Setaria viridis), watergrass (Echinochloa crusgalli) and wild oat (Avena fatua). Broadleaf weeds utilized were annual morningglory (Ipomoea purpurea), velvetleaf (Abutilon theophrasti) and wild mustard (Brassica kaber).

Solutions of the test compounds were made by weighing out 333 mg of the compound in question into a bottle, and dissolving it in 25 ml of acetone containing 1% polyoxyethylene sorbitan monolaurate emulsifier to form a stock solution. Additional solvents, not exceeding 5 ml, were used if needed to dissolve the compound. An aliquot was taken from the stock solution and diluted with a 19:1 water:acetone mixture containing 1% of the emulsifier to form a sprayable solution.

The flats were placed in a greenhouse at 70°-85° F. (21.1°-29.5° C.) and watered by sprinkling. One day after planting the flats were sprayed with the solutions of the test compounds at a rate of 80 gallons of solution per acre with the compound being applied at a rate of 4 pounds per acre (4.48 kg/ha).

The flats were returned to the greenhouse after spraying and watered daily by sprinkling. The degree of weed control was estimated and recorded 3 weeks after treatment, as percentage control compared to the growth of the same species in an untreated check flat of the same age.

The percent control is based on the total injury to the plants due to all factors, including inhibited germination, killing of the plant tissue after emergence, stunting, malformation, chlorosis, and other types of injury. The control ratings vary from 0 to 100 percent, where 0 represents no effect with growth equal to the untreated control, and 100 represents complete kill.

POST-EMERGENCE HERBICIDAL EVALUATION

The soil was prepared and seeded with the same varieties as described for the pre-emergence test. The flats were placed in the greenhouse at 70°-85° F. (21.1°-29.5° C.) and watered by sprinkling. Twelve to fourteen days after planting, the flats were sprayed on a table at a rate of 80 gallons of solution per acre. The compound was applied at the rate of 4 pounds/ acre (4.48 kg/ha). The spray solution was made up similarly to that described for the pre-emergence evaluation.

The flats were returned to the greenhouse after spraying and watered daily without wetting the foliage. Three weeks after treatment the degree of weed control was estimated and recorded as percentage control compared to the growth of the same species in an untreated check flat of the same age. The percent control ratings were assigned on the same basis as for the pre-emergence evaluation.

The following Table II contains the results of these tests in terms of average control of the three grasses and three broadleaf weeds, respectively, in both pre- and post-emergence evaluations. Control of nutsedge is not included in this table for convenience, as most of the compounds showed no or practically no control of nutsedge in these tests. Some compounds, however, notably Compounds 70, 71, 72, 76, 79, 80, 129, 130, 132, 138, 141, 150, 155, 156, 161, 162, 172, 173, 185, 186, 188, 189 and 190 did demonstrate activity against nutsedge.

It should be noted that even those compounds which (from the following table) indicate a relatively low average control of weeds, nevertheless showed good activity against at least one weed in these tests, which in many cases was wild mustard.

                  TABLE II                                                         ______________________________________                                                    Pre-emergence Control                                                                         Post-emergence Control                               Compound   (average)      (average)                                            Number     grasses broadleaf  grasses                                                                              broadleaf                                  ______________________________________                                         1          23      43         10    53                                         2          30      73         20    83                                         3          28      0          27    47                                         4          28      82         7     65                                         5          23      67         10    72                                         6          0       42         --    --                                         7          73      73         50    78                                         8          7       63         30    63                                         9          0       37         3     55                                         10         2       48         13    73                                         11         2       42         13    57                                         12         42      85         27    63                                         13         20      32         2     23                                         14         17      30         2     22                                         15         27      35         2     25                                         16         33      47         5     25                                         17         47      73         13    25                                         18         93      83         38    50                                         19         95      97         68    60                                         20         95      95         80    70                                         21         93      93         50    57                                         22         93      47         60    67                                         23         92      77         65    80                                         24         90      63         60    67                                         25         93      63         67    73                                         26         90      87         63    73                                         27         93      90         67    73                                         28         92      75         63    63                                         29         67      53         37    37                                         30         93      95         73    73                                         31         97      100        83    78                                         32         93      90         63    73                                         33         97      100        82    73                                         34         95      95         85    85                                         35         30      10         10    40                                         36         0       0          0     20                                         37         40      32         10    33                                         38         77      53         53    60                                         39         85      53         23    40                                         40         33      63         47    50                                         41         93      100        87    83                                         42         83      73         67    80                                         43         93      100        83    80                                         44         95      80         80    83                                         45         67      63         57    80                                         46         37      57         13    47                                         47         23      37         13    50                                         48         77      93         50    73                                         49         28      53         13    47                                         50         43      60         10    80                                         51         97      88         73    87                                         52         97      93         78    77                                         53         63      80         20    65                                         54         100     93         83    83                                         55         100     100        85    92                                         56         97      47         27    60                                         57         97      85         78    93                                         58         90      85         23    90                                         59         45      22         10    40                                         60         60      42         20    60                                         61         35      10         13    50                                         62         72      37         13    50                                         63         93      67         65    87                                         64         87      75         43    77                                         65         73      37         13    30                                         66         43      33         2     13                                         67         83      57         27    67                                         68         88      57         43    60                                         69         80      28         7     27                                         70         100     100        88    80                                         71         98      100        83    80                                         72         98      100        85    80                                         73         100     100        87    57                                         74         100     100        85    80                                         75         100     100        87    80                                         76         100     100        87    83                                         77         98      100        87    80                                         78         98      100        77    83                                         79         98      100        85    83                                         80         98      97         80    80                                         81         70      93         60    77                                         82         83      88         72    70                                         83         88      82         73    87                                         84         100     100        83    83                                         85         98      100        87    83                                         86         98      100        80    83                                         87         72      90         57    80                                         88         75      92         47    73                                         89         88      83         53    73                                         90         95      95         60    73                                         91         95      92         67    73                                         92         97      100        87    73                                         93         93      92         60    60                                         94         75      63         47    53                                         95         97      97         72    73                                         96         95      97         80    73                                         98         80      63         60    47                                         98         97      97         70    73                                         99         85      90         33    73                                         100        97      100        73    80                                         101        97      98         80    83                                         102        98      100        83    80                                         103        98      100        80    80                                         104        100     98         80    80                                         105        98      100        82    80                                         106        98      100        82    80                                         107        100     100        82    80                                         108        98      100        80    80                                         109        82      98         33    80                                         110        97      97         80    75                                         111        98      100        33    87                                         112        83      82         27    80                                         113        95      87         57    80                                         114        95      100        40    80                                         115        100     83         67    67                                         116        100     100        88    87                                         117        100     100        87    87                                         118        100     100        87    80                                         119        100     100        92    90                                         120        100     63         43    67                                         121        97      78         85    60                                         122        20      75         0     90                                         123        5       8          2     53                                         124        80      100        70    97                                         125        98      100        93    70                                         126        98      100        97    100                                        127        93      100        53    50                                         128        97      100        87    88                                         129        100     100        87    87                                         130        95      100        95    95                                         131        85      40         73    67                                         132        100     100        98    93                                         133        50      67         27    77                                         134        50      30         10    40                                         138        100     100        87    57                                         139        97      92         60    73                                         140        70      100        80    90                                         141        100     100        87    90                                         142        100     100        87    87                                         143        95      97         73    73                                         144        87      92         83    80                                         145        77      63         63    68                                         146        95      100        68    100                                        150        100     100        100   100                                        151        50      73         47    60                                         152        97      70         53    92                                         153        70      100        73    63                                         154        67      43         20    0                                          155        47      70         60    70                                         156        97      100        80    87                                         157        73      100        87    90                                         158        40      40         7     58                                         159        77      40         3     33                                         160        100     80         23    87                                         161        100     100        97    100                                        162        100     100        100   100                                        163        98      100        67    60                                         164        97      40         37    33                                         165        100     58         60    50                                         166        73      63         37    40                                         167        97      47         77    57                                         168        100     67         57    73                                         169        93      80         60    82                                         170        100     63         30    10                                         171        93      80         33    23                                         172        100     83         80    93                                         173        100     93         80    97                                         174        100     100        100   100                                        175        100     100        100   100                                        176        97      95         100   82                                         177        83      73         75    60                                         178        70      45         73    73                                         179        73      50         67    53                                         180        87      93         90    53                                         181        83      93         80    60                                         182        80      70         83    87                                         183        100     93         88    83                                         184        100     100        93    97                                         185        100     100        93    100                                        186        100     100        97    97                                         187        95      100        93    83                                         188        100     100        93    83                                         189        100     100        88    80                                         190        100     100        87    80                                         191        43      73         0     60                                         192*       100     98         98    85                                         193*.sup.a 100     100        93    97                                         194*       70      87         30    53                                         195*       50      47         0     37                                         196*       93      100        67    87                                         197*       97      100        47    70                                         198*       93      100        80    80                                         199*       100     100        95    93                                         200*       100     100        63    90                                         201*       100     67         50    80                                         202*       100     100        100   97                                         203*       100     100        100   80                                         204*       100     100        78    80                                         205*       100     100        100   90                                         206*       100     100        98    95                                         207*       100     100        100   63                                         208        100     63         53    33                                         209        100     93         93    93                                         210        60      80         40    37                                         211        100     100        90    83                                         212        98      85         77    93                                         213        95      67         47    67                                         214        95      87         73    83                                         215        70      33         30    10                                         ______________________________________                                          .sup.a Rated at 18 days after treatment.                                       *Treatment = 2 lb/Acre.                                                  

FURTHER HERBICIDAL EVALUATION

Compounds showing good activity in the evaluations described above were submitted for one or more subsequent evaluations involving, for example, different weeds, lower application rates, varying application procedures, and/or selectivity with respect to crops. The weeds employed in these tests included those utilized in the tests just described, as well as a number of others such as one or more species of ryegrass (Lolium), Sorghum, signalgrass (Brachiaria), cocklebur (Xanthium), Sesbania, Cassia, Alopecurus, oats (Avena), bluegrass (Poa), Matricaria, chickweed (Stellaria), bedstraw (Galium), and violet (Viola). Crops which were variously employed in these evaluations included cotton (Gossypium hirsutum), soybean (Glycine max), corn (Zea maize), milo (Sorghum bicolor), wheat (Tritium aestivum), sugarbeet (Beta vulgaris), rice (Oryza sativa), carrot (Daucus carots), and barley (Hordeum vulgare).

In summation, compounds submitted for further evaluation showed varying activity depending on the compound and the evaluation employed. Some compounds showed a better activity in controlling grasses, others in controlling broadleaf weeds. Some compounds demonstrated better activity in pre-emergence application, others in post-emergence application. Some compounds demonstrated good activity in nearly all types of application. Some compounds demonstrated good control in tests at application rates ranging as low as 0.06 pound per acre (0.065 kg/ha).

With respect to injury to crops, nearly all compounds tested produced unacceptable injury to sugarbeets even at relatively low levels of application. Some compounds showed good broad-spectrum activity but relatively low selectivity, causing injury to both weeds and crops in the same tests. Other compounds showed varying selectivity to certain crops, particularly cereals, such as wheat, rice and corn, most notably with respect to rice in various methods of application. A number of compounds also demonstrated selectivity in controlling weeds in the presence of cotton.

In practice, a pure compound can be used as a herbicide. However, in general, the compounds are first formulated with one or more inert carriers or diluents suitable for herbicidal use, before being applied.

The compositions or formulations, including a compound as described herein, may exist in any one of a number of solid or liquid forms. Examples of solid forms are dusts, granules, tablets, powders and the like. Examples of liquid forms are emulsifiable concentrates, flowables and pastes. Such compositions may contain, in addition to the active compound or compounds, various carriers or diluents; surface active agents (wetting agents, dispersing agents and/or emulsifying agents); solvents (water, or organic solvents such as aromatic solvents or chlorinated aliphatic solvents); adhesives; thickeners; binders; antifoaming agents; and other substances as mentioned herein. Solid carriers or diluents included in such compositions or formulations may include, for example, ground natural minerals such as kaolins, alumina, calcium carbonate, silica, kieselguhr, clay, etc.; ground synthetic minerals such as various silicates and aluminosilicates and ground vegetable products such as bark, cornmeal, sawdust, cellulose powder and the like.

To manufacture solid compositions, the active substances are mixed with solid carriers or diluents such as those mentioned above and the mixture is ground to the appropriate size. Granules can be manufactured by dissolving an active compound in an organic solvent and applying the mixture, for example, by atomization, onto an absorptive granulated inert material, such as silica. Adhesives may be utilized to assist in the incorporation of the compound onto the solid particles. Pellets or granules can be manufactured by extrusion with appropriate carriers and binders.

Wettable powders, flowables, and pastes are obtained by mixing and grinding an active compound with one or more dispersing agents and/or solid carriers or diluents. Also included may be wetting agents and/or dispersing agents, for example, lignins, methyl cellulose, naphthalenesulfonic acid derivatives, fatty alcohol sulfates and various types of alkali and alkaline earth metal salts of fatty acids.

Emulsifiable concentrates are generally obtained by dissolving the active compound in an organic solvent, for example, butanol, cyclohexanone, xylenes, or higher boiling aromatic hydrocarbons. To obtain suspensions or emulsions in water, wetting agents are generally also added.

It is possible to use highly concentrated liquid compositions containing up to about 95% by weight of the active compound, or even the active compound alone for those compounds which are liquids, when applying the compound in the form of a finely divided liquid by use of various atomizing equipment, for example by airplane crop spraying techniques. For other purposes, however, the various types of compositions which can be utilized for these compounds will contain varying amounts of the compound according to the type of composition and the intended use.

In general, compositions may contain from 0.1 to 95% of the active compound, more preferably from 0.5 to 90%. Some typical compositions will contain an active compound as follows: wettable powders, flowables and pastes--20 to 90% active compound; oil suspensions, emulsions, solutions and emulsifiable concentrates--5 to 90% active compound; aqueous suspensions--10 to 50% active compound; dusts and powders--1 to 25% active compound; granules and pellets--1 to 20% active compound.

The rate of application of the active compound to a locus to be controlled will depend on the activity of the compound and/or composition and the nature of the seeds and plants to be controlled and will vary from about 0.05 to about 50 pounds per acre (about 0.06 to about 56 kg/ha).

In addition to the active compound and the various agents utilized in preparing compositions and formulations mentioned above, such compositions may also contain one or more other active compounds of the type mentioned herein as well as other pesticidal agents, such as herbicides, fungicides, insecticides, acaricides, nematocides, bactericides, and plant growth regulators. Such compositions may also contain soil disinfectants or fumigants and may further contain fertilizers, thus making it possible to provide multi-purpose compositions containing one or more of the compounds described herein as well as, optionally, other pesticides and also fertilizers, all intended and formulated for use at the same locus.

Compositions containing one or more of the active compounds described, in a herbicidally effective amount, may be applied to the plant or locus to be controlled in any conventional manner. Thus, powders and various liquid compositions containing the active compound can be applied by the use of power dusters, boom and hand sprayers and spray dusters, or applied from airplanes as mists or sprays. When applied in the latter method they may be effective in very low dosages. To modify or control growth of germinating seeds or emerging seedlings liquid compositions may be applied to the soil with conventional methods and may be distributed in the soil to a depth of one-half inch below the soil surface. The compositions need not be admixed with the soil particles but can be applied merely by sprinkling on the surface of the soil.

Compositions including active compounds may also be applied by addition to irrigation waters supplied to the field to be treated. This method of application permits penetration of the compounds into the soil as the water is absorbed therein.

    ______________________________________                                         EXAMPLES OF TYPICAL COMPOSITIONS                                               ______________________________________                                         Ingredient            Weight %                                                 ______________________________________                                         Oil                                                                            Active Compound       1                                                        Oil solvent-heavy aromatic naphtha                                                                   99                                                       Total                 100                                                      Emulsifiable Concentrate                                                       Active Compound       50                                                       Kerosene              45                                                       Emulsifying agent (mixture of long                                             chain ethoxylated polyethers with                                              long chain sulfonate) 5                                                        Total                 100                                                      Emulsifiable Concentrate                                                       Active Compound       90                                                       Kerosene              5                                                        Emulsifying agent (mixture of long                                             chain ethoxylated polyethers with                                              long chain sulfonate) 5                                                        Total                 100                                                      ______________________________________                                         Dusts and/or Powders                                                           Ingredient       Wt. %    Wt. %    Wt. %                                       ______________________________________                                         Active Compound  0.5      50.0     90.0                                        Attapulgite Clay Powder                                                                         93.5     44.0     4.0                                         Sodium lignin sulfonate                                                                         5.0      5.0      5.0                                         Sodium dioctyl sulfosuccinate                                                                   1.0      1.0      1.0                                         Total            100.0    100.0    100.0                                       ______________________________________                                     

What is claimed is:
 1. A compound having the formula ##STR62## in which R is halo, trihalomethyl, pentahaloethyl, mono- or difluoromethyl, mono-, di-, tri- or tetrafluoroethyl, fluoroalkylthio, fluoroalkoxy, methylthio, methylsulfonyl, halomethylsulfonyl, C₁ -C₂ alkyl, or methoxy;n is 1 or 2, provided that:(a) if n is 1 and R is other than fluoro, the substituent R is located at the 3-position on the phenyl ring; and (b) if n is 2, the substituents R are located at the 3- and 4-positions on the phenyl ring; R₁ is hydrogen, C₁ -C₃ alkyl, C₁ -C₃ alkoxy, C₁ -C₂ alkylthio, C₃ -C₄ alkenylthio, C₁ -C₄ alkylsulfonyl, C₁ -C₄ alkylsulfinyl, cyano, carbamyl, C₁ -C₄ mono-alkylcarbamyl, C₁ -C₂ carboalkoxy, or NR₃ R₄ in which R₃ and R₄ are independently hydrogen, C₁ -C₄ alkyl or C₂ -C₄ alkenyl; and R₂ is hydrogen, phenyl; mono- or disubstituted phenyl in which the substituents are selected from halo, cyano, and trihalomethyl; C₁ -C₄ mono- or dialkylcarbamyl; phenylcarbamyl; C₁ -C₄ mono-alkylthiocarbamyl; C₄ -C₆ ketoalkenyl; cyano; C₁ -C₄ alkylsulfonyl; C₁ -C₄ haloalkylsulfonyl; or ##STR63## in which Y is oxygen or sulfur; m is 0 or 1; and R₅ is C₁ -C₁₀ alkyl; C₂ -C₁₀ alkenyl; C₂ -C₈ alkynyl if m is 0; C₃ -C₈ alkynyl in which the triple bond is separated from the oxygen or sulfur atom (Y) by at least one methylene group is m is 1; C₁ -C₈ haloalkyl if m is 0; C₂ -C₈ haloalkyl if m is 1; C₂ -C₁₀ alkoxyalkyl if m is 0; pyridyl if m is 0; C₃ -C₁₀ alkoxyalkyl in which the alkylene portion has at least two carbon atoms if m is 1; or R₅ is

    (R.sub.6).sub.p R.sub.7

in which p is 0 or 1; R₆ is a C₁ -C₂ alkylene group and R₇ is phenyl, halo-substituted phenyl, C₃ -C₇ cycloalkyl, optionally substituted by from 1 to 3 methyl groups; C₁ -C₄ carboalkoxy; or a saturated or unsaturated heterocyclic ring containing from 5 to 6 atoms including from 1 to 2 hetero atoms selected from oxygen and sulfur, optionally substituted by from 1 to 3 methyl groups and optionally substituted by from 1 to 2 oxo groups; provided that when R₁ is methylthio and R₂ is isopropylcarboxy, then R is not 2-fluoro.
 2. A compound according to claim 1 in which n is
 1. 3. A compound according to claim 2 in which R is substituted on the phenyl ring at the 3-position.
 4. A compound according to claim 1 in which R₁ is C₁ -C₃ alkyl.
 5. A compound according to claim 1 in which R₁ is C₁ -C₃ alkoxy.
 6. A compound according to claim 1 in which R₁ is C₁ -C₂ alkylthio.
 7. A compound according to claim 1 in which R₁ is N-R₃ R₄.
 8. A compound according to claim 7 in which R₃ is hydrogen.
 9. A compound according to claim 7 in which both R₃ and R₄ are C₁ -C₄ alkyl.
 10. A compound according to claim 1 in which R₁ is C₁ -C₄ alkylsulfonyl.
 11. A compound according to claim 1 in which n is
 2. 12. A compound according to claim 1 in which R₂ is ##STR64##
 13. A compound according to claim 12 in which m is
 0. 14. A compound according to claim 13 in which R₅ is C₁ -C₁₀ alkyl.
 15. A compound according to claim 13 in which R₅ is C₂ -C₁₀ alkenyl.
 16. A compound according to claim 13 in which R₅ is C₁ -C₈ haloalkyl.
 17. A compound according to claim 13 in which R₅ is C₂ -C₁₀ alkoxyalkyl.
 18. A compound according to claim 13 in which R₅ is (R₆)_(p) R₇ and p is
 0. 19. A compound according to claim 18 in which R₇ is phenyl or halo-substituted phenyl.
 20. A compound according to claim 18 in which R₇ is C₃ -C₇ cycloalkyl, optionally substituted by from 1 to 3 methyl groups.
 21. A compound according to claim 18 in which R₇ is C₁ -C₄ carboalkoxy.
 22. A compound according to claim 18 in which R₇ is a saturated or unsaturated 5- or 6-member heterocyclic ring, including from 1 to 2 hetero atoms selected from oxygen and sulfur, optionally substituted by from 1 to 3 methyl groups and optionally including from 1 to 2 oxo groups.
 23. A compound according to claim 22 in which the heterocyclic ring is a furanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxolanyl, dioxanyl, or tetrahydrothienyl ring.
 24. A compound according to claim 13 in which R₅ is (R₆)_(p) R₇ and p is
 1. 25. A compound according to claim 24 in which R₆ is methylene.
 26. A compound according to claim 25 in which R₇ is phenyl or halo-substituted phenyl.
 27. A compound according to claim 25 in which R₇ is C₃ -C₇ cycloalkyl, optionally substituted by from 1 to 3 methyl groups.
 28. A compound according to claim 25 in which R₇ is C₁ -C₄ carboalkoxy.
 29. A compound according to claim 25 in which R₇ is a saturated or unsaturated 5- or 6-member heterocyclic ring, including from 1 to 2 hetero atoms selected from oxygen and sulfur, optionally substituted by from 1 to 3 methyl groups and optionally including from 1 to 2 oxo groups.
 30. A compound according to claim 29 in which the heterocyclic ring is a furanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxolanyl, dioxanyl, or tetrahydrothienyl ring.
 31. A compound according to claim 12 in which m is 1 and Y is sulfur.
 32. A compound according to claim 12 in which m is 1 and Y is oxygen.
 33. A compound according to claim 32 in which R₅ is C₁ -C₁₀ alkyl.
 34. A compound according to claim 33 in which R₅ is C₁ -C₆ alkyl.
 35. A compound according to claim 32 in which R₅ is C₂ -C₁₀ alkenyl.
 36. A compound according to claim 32 in which R₅ is C₂ -C₈ haloalkyl.
 37. A compound according to claim 32 in which R₅ is C₃ -C₁₀ alkoxyalkyl, in which the alkylene portion contains at least two carbon atoms.
 38. A compound according to claim 32 in which R₅ is (R₆)_(p) R⁷ and p is
 0. 39. A compound according to claim 38 in which R₇ is phenyl or halo-substituted phenyl.
 40. A compound according to claim 38 in which R₇ is C₃ -C₇ cycloalkyl, optionally substituted by from 1 to 3 methyl groups.
 41. A compound according to claim 38 in which R₇ is C₁ -C₄ carboalkoxy.
 42. A compound according to claim 38 in which R₇ is a saturated or unsaturated 5- or 6-member heterocyclic ring, including from 1 to 2 hetero atoms selected from oxygen and sulfur, optionally substituted by from 1 to 3 methyl groups and optionally including from 1 to 2 oxo groups.
 43. A compound according to claim 42 in which the heterocyclic ring is a furanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxolanyl, dioxanyl, or tetrahydrothienyl ring.
 44. A compound according to claim 32 in which R₅ is (R₆)_(p) R₇ and p is 1 or
 2. 45. A compound according to claim 44 in which R₆ is methylene.
 46. A compound according to claim 45 in which R₇ is phenyl or halo-substituted phenyl.
 47. A compound according to claim 45 in which R₇ is C₃ -C₇ cycloalkyl, optionally substituted by from 1 to 3 methyl groups.
 48. A compound according to claim 45 in which R₇ is C₁ -C₄ carboalkoxy.
 49. A compound according to claim 45 in which R₇ is a saturated or unsaturated 5- or 6-member heterocyclic ring, including from 1 to 2 hetero atoms selected from oxygen and sulfur, optionally substituted by from 1 to 3 methyl groups and optionally including from 1 to 2 oxo groups.
 50. A compound according to claim 49 in which the heterocyclic ring is a furanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxolanyl, dioxanyl, or tetrahydrothienyl ring.
 51. A compound according to claim 1 in which R₂ is C₁ -C₄ alkylcarbamyl.
 52. A compound according to claim 51 in which R₂ is C₁ -C₄ monoalkylcarbamyl.
 53. A compound according to claim 1 in which R₂ is C₁ -C₄ alkylsulfonyl or C₁ -C₄ haloalkylsulfonyl.
 54. A compound according to claim 1 in which R₂ is phenyl or substituted phenyl.
 55. A compound according to claim 1 in which R₂ is hydrogen and R₁ is other than alkylsulfinyl or alkylsulfonyl.
 56. A hydrohalide salt of a compound according to claim
 55. 57. A compound according to claim 1 in which R is 3-trifluoromethyl.
 58. A compound according to claim 57 in which R₁ is methylthio and R₂ is 4-fluorophenyl.
 59. A compound according to claim 57 in which R₁ is dimethylamino and R₂ is 4-cyanophenyl.
 60. A compound according to claim 57 in which R₁ is methylthio and R₂ is isopropylcarbamyl.
 61. A compound according to claim 57 in which R₁ is methylthio and R₂ is carboisopropoxyl.
 62. A compound according to claim 57 in which R₁ is methylthio and R₂ is isovaleroyl.
 63. A compound according to claim 57 in which R₁ is dimethylamino and R₂ is carboisopropoxy.
 64. A compound according to claim 57 in which R₁ is methylthio and R₂ is carboethoxy.
 65. A compound according to claim 57 in which R₁ is methylthio and R₂ is carbo-isopropylthio.
 66. A compound according to claim 57 in which R₁ is ethyl and R₂ is carboisopropoxy.
 67. A compound according to claim 57 in which R₁ is methoxy and R₂ is carboisopropoxy.
 68. A compound according to claim 57 in which R₁ is methoxy and R₂ is isopropylcarbamyl.
 69. A compound according to claim 57 in which R₁ is methoxy and R₂ is isovaleroyl.
 70. A compound according to claim 57 in which R₁ is dimethylamino and R₂ is isovaleroyl.
 71. A compound according to claim 57 in which R₁ is methoxy and R₂ is carboisopropylthio.
 72. A compound according to claim 57 in which R₁ is methoxy and R₂ is carboisopropenyloxy.
 73. A compound according to claim 57 in which R₁ is methoxy and R₂ is 3,3-dimethylacryloyl.
 74. A compound according to claim 57 in which R₁ is methylthio and R₂ is acetyl.
 75. A compound according to claim 57 in which R₁ is methylthio and R₂ is 3,3-dimethylacryloyl.
 76. A compound according to claim 57 in which R₁ is methylthio and R₂ is isohexanoyl.
 77. A compound according to claim 57 in which R₁ is methylthio and R₂ is 3-methylvaleroyl.
 78. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbomethoxy.
 79. A compound according to claim 57 in which R₁ is methoxy and R₂ is carboethoxy.
 80. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-n-propoxy.
 81. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-n-butoxy.
 82. A compound according to claim 57 in which R₁ is methoxy and R₂ is carboallyloxy.
 83. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-sec-butoxy.
 84. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-(2-chloroethoxy).
 85. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-(2-methoxyethoxy).
 86. A compound according to claim 57 in which R₁ is ethoxy and R₂ is carboisopropoxy.
 87. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbocyclopentyloxy.
 88. A compound according to claim 57 in which R₁ is methoxy and R₂ is n-propionyl.
 89. A compound according to claim 57 in which R₁ is methoxy and R₂ is n-butyryl.
 90. A compound according to claim 57 in which R₁ is methoxy and R₂ is 4-methylvaleroyl.
 91. A compound according to claim 57 in which R₁ is methoxy and R₂ is 4-chloro-n-butyryl.
 92. A compound according to claim 57 in which R₁ is methoxy and R₂ is 4-chloro-n-butyryl.
 93. A compound according to claim 57 in which R₁ is methoxy and R₂ is 2-methylvaleroyl.
 94. A compound according to claim 57 in which R₁ is ethyl and R₂ is isovaleroyl.
 95. A compound according to claim 57 in which R₁ is ethyl and R₂ is carbo-n-propoxy.
 96. A compound according to claim 57 in which R₁ is ethyl and R₂ is carbo-isobutoxy.
 97. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-(2-methylcyclopentyloxy).
 98. A compound according to claim 57 in which R₁ is methyl and R₂ is carboisopropoxy.
 99. A compound according to claim 57 in which R₁ is methyl and R₂ is isovaleroyl.
 100. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-(3-methylcyclopentyloxy).
 101. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-3-tetrahydrofuranyloxy.
 102. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-2-tetrahydropyranylmethoxy.
 103. A compound according to claim 57 in which R₁ is methoxy and R₂ is carbo-2-tetrahydrofuranylmethoxy.
 104. A compound according to claim 57 in which R₁ is methoxy and R₂ is cyclopropylcarboxy.
 105. A compound according to claim 1 in which R is 3-chloro.
 106. A compound according to claim 105 in which R₁ is methylthio and R₂ is isovaleroyl.
 107. A compound according to claim 105 in which R₁ is methoxy and R₂ is carboisopropoxy.
 108. A compound according to claim 105 in which R₁ is methoxy and R₂ is isovaleroyl.
 109. A compound according to claim 105 in which R₁ is methoxy and R₂ is isopropylcarbamyl.
 110. A compound according to claim 1 in which R is 3-trifluoromethylthio.
 111. A compound according to claim 110 in which R₁ is methoxy and R₂ is carboisopropoxy.
 112. A compound according to claim 110 in which R₁ is methoxy and R₂ is isovaleroyl.
 113. A compound according to claim 110 in which R₁ is methylthio and R₂ is carboisopropoxy.
 114. A compound according to claim 110 in which R₁ is methylthio and R₂ is isovaleroyl.
 115. A compound according to claim 57 in which R₁ is hydrogen and R₂ is carboisopropyl.
 116. A compound according to claim 1 in which R is difluoromethoxy.
 117. A compound according to claim 1 in which R₁ is methoxy and R₂ is carboisopropoxy.
 118. A compound according to claim 1 in which R is 3-trifluoromethoxy.
 119. A compound according to claim 1 in which R₁ is methoxy and R₂ is carboisopropoxy.
 120. A compound according to claim 57 in which R₁ is methylthio and R₂ is 4-carbopyridyl.
 121. A compound according to claim 1 in which R is 3-tetrafluoroethoxy.
 122. A compound according to claim 121 in which R is 1,1,2,2-tetrafluoromethoxy.
 123. A compound according to claim 122 in which R₁ is methylthio and R₂ is carbofuranyl.
 124. A compound according to claim 122 in which R₁ is methylthio and R₂ is carboisopropoxy.
 125. A compound according to claim 122 in which R₇ is C₃ -C₇ cycloalkyl, optionally substituted by from 1 to 3 methyl groups.
 126. An herbicidal composition comprising(a) an herbicidally effective amount of a compound according to claim 1; and (b) an herbicidally suitable diluent or carrier.
 127. A method of controlling undesirable vegetation comprising applying to said vegetation or to the locus where control is desired, a herbicidally effective amount of a compound according to claim
 1. 128. A method of controlling undesirable vegetation comprising applying to said vegetation or to the locus where control is desired, a herbicidally effective amount of a composition according to claim
 126. 129. A method for selectively controlling undesirable vegetation in the presence of a crop comprising applying to a locus where control is desired a selectively herbicidally effective amount of a compound according to claim
 1. 130. A method according to claim 129 in which the crop is a cereal crop.
 131. A method according to claim 130 in which the cereal crop is rice. 